Why do W8 apps take so long to open?

I've had Windows 8 since the Release Preview edition back in August. Ever since then, I've wondered why 'Metro' apps take so long to open. The photo app can take 10 seconds from animation to actually displaying the picture. In comparison, the basic photo viewer in desktop mode opens the same picture in a quarter of a second. Other metro apps are like this too. Is this intentional? Is there anyone that actually likes this?

Specs:

AMD FX4170 Quad core @ 4.2GHZ

16GB 1666mhz RAM

500GB Seagate 7200rpm

Nvidia GT430

(Edited-in specs)